Ultrashteld devices and methods for use in ultrasonic procedures

ABSTRACT

Devices and method are provided for ultrasound transmission without the need for external couplants, such as gels, which are typically used in conventional ultrasound procedures. In particular, ultrashields are provided for use with ultrasound probes, wherein the ultrashields have specialized layers to provide an uninterrupted pathway of acoustic conductance from the probe to the surface of the body throughout the procedure while introducing minimal to no attenuation of ultrasound wave transmission. In addition, combinations of ultrashields and probe covers are provided to provide additional features such as a microbial barrier.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/249,724, filed Jan. 16, 2019, which is a continuation of U.S. patentapplication Ser. No. 15/476,468, filed Mar. 31, 2017, now U.S. Pat. No.10,206,653, which is a continuation of U.S. patent application Ser. No.15/332,571, filed, Oct. 24, 2016, now U.S. Pat. No. 10,064,599, whichclaims priority to U.S. Provisional Patent Application No. 62/285,758entitled An Ultrasonic Couplant Design and Probe Cover Design to ReplaceUse of Ultrasonic Gel During Ultrasound Imaging, filed on Nov. 9, 2015,each of which are incorporated herein by reference for all purposes.

BACKGROUND OF THE INVENTION

The term “ultrasound” typically applies to acoustic energy with afrequency above human hearing (20,000 hertz or 20 kilohertz). When usedin medical applications, ultrasound is typically between 1 and 30 MHzfor imaging and flow measurements and between 0.05 and 1.00 MHz fortherapy. The application of ultrasound in medicine began in the 1950s.It was first introduced in the field of obstetrics. Obstetric sonographyis the use of medical ultrasonography in pregnancy, in which sound wavesare used to create real-time visual images of the developing embryo orfetus in its mother's uterus. The procedure is a standard part ofprenatal care in many countries, as it can provide a great deal ofinformation about the health of the mother, the timing and progress ofthe pregnancy, and the health and development of the embryo or fetus.After that, the use of ultrasound propagated to nearly all fields ofmedicine including abdominal diagnostics, cardiology, urology,cerebrovascular, ophthalmology, orthopedics, breast examination, andpediatrics. Ultrasound has been proven to provide fast, accurate andsafe patient imaging for an expanding array of diagnostic andtherapeutic applications with ongoing technologic improvements and thegrowing recognition of harmful radiation from other imaging modalities.

Sonographers typically use a hand-held probe (called a transducer) thatis placed directly on and moved over the patient. With the use of theprobe, the sonographer is able to visualize body structures under theskin including tendons, muscles, joints, nerves, vessels and internalorgans for possible pathology or lesions. Current probes utilizereflection technology. The probe transmits high-frequency ultrasoundsound pulses into the body. The pulses are produced by a piezoelectrictransducer within the probe. Strong, short electrical pulses from theultrasound machine cause the crystals to change shape rapidly. The rapidshape changes, or vibrations, of the crystals produce sound waves thattravel outward. The ultrasound wave travels into the body until itencounters a boundary between tissues (e.g. between fluid and softtissue, soft tissue and bone). Some of the ultrasound waves getreflected back to the probe, while some travel on further until theyreach another boundary and get reflected. The reflected waves are pickedup and interpreted by the probe to produce a real-time two-dimensionalrepresentation on a monitor. Interpretation through the probe occurswhen the reflected sound or pressure waves hit the piezoelectriccrystals which causes them to emit electrical currents. Thus, the samecrystals can be used to send and receive sound waves. The probe also hasa sound absorbing substance to eliminate back reflections from the probeitself. The electric currents generated by the reflected waves arerelayed to the ultrasound machine. The ultrasound machine is able tocalculate the distance from the probe to the tissue or organ(boundaries) using the speed of sound in tissue (5,005 ft/s or 1,540m/s) and the time of each echo's return (usually on the order ofmillionths of a second). The ultrasound machine then displays thedistances and intensities of the echoes on the screen, forming atwo-dimensional image. 3D images can be generated by acquiring a seriesof adjacent 2D images by simply moving or tilting the probe on thepatient.

In order for the maximal transmission of energy from one medium toanother (i.e, from the probe through the skin), the impedance of the twomedia should be nearly the same. Clearly, in the case of ultrasoundwaves passing from the probe to the tissues, this cannot be readilyachieved. The greater the difference in impedance at a boundary, thegreater the reflection that will occur, and therefore, the smaller theamount of energy that will be transferred. With decreased sound wavestransferred, there is less energy to be reflected and interpreted by theprobe. The difference in impedance is greatest for the probe/airinterface which is the first one that the ultrasound has to overcome inorder to reach the body. Therefore, maintaining constant and optimalcontact between the probe and skin is important for the utilization ofultrasound technology. To minimize this difference, a suitable couplingmedium is typically used. The coupling media used in this contextincludes various oils, creams and gels. The most popular is gel which isapplied to the probe head and/or the body of the patient. The ultrasoundcoupling gel displaces air and fills contours between the piezoelectriceye, or transducer, of an ultrasound instrument (such as a probe orscanhead), which converts energy between electrical and acoustic, andthe body into which the sound is being directed. Examples of ultrasoundprobes or scanheads can be found in U.S. Pat. No. 5,482,047 to Nordgrenet al. or U.S. Pat. No. 5,207,225 to Oaks et al. This gel or fluidmaterial, by nature of its physical and acoustic properties, serves asan ultrasound acoustic coupler between the ultrasound transducer andtissue, thereby acoustically joining the two, so that the ultrasoundbased information developed can freely pass back and forth between thebody and the transducer.

Because of the coupling effect, this media is commonly referred to as anultrasound couplant, ultrasound gel, scanning gel, ultrasoundtransmission media or acoustic transmission media. Many fluids andwater-based gels have been used as ultrasound couplants over the years.Early use of mineral oil was replaced by gels whose thickness wasprovided from a polymer group consisting of a copolymer of methyl vinylether, maleic anhydride, carboxy polymethylene polymer and mixturesthereof, or from a mixture of carboxy polymethylene polymer neutralizedwith an alkaline agent as a primary thickener together with hydroxyalkyl cellulose as an auxiliary thickener and a polyalkylene glycol suchas propylene glycol as a humectant, as described in U.S. Pat. No.4,002,221 to Buchalter and U.S. Pat. No. 4,459,854 to Richardson et al.

Fluids and gels commonly used as ultrasound couplants have severalfundamental disadvantages, some of which are described herein. To begin,patients often find the fluid or gel to be cold, sticky and messy. Thefluids or gels are difficult to contain on, and remove from, the patientduring and after the ultrasound procedure. Further, commerciallyavailable oils and water based gels often introduce problems to theelectronics by their chemically degrading nature. They may react withthe adhesives, elastomers, and epoxies used in the construction ofmedical ultrasound transducers, thus appreciably degrading performanceand shortening their service life. With therapeutic interventions suchas needle biopsies or nerve blocks, the gels may be introduced into thebody which introduces additional infectious or inflammatory risks to thepatient as described in further detail below.

In addition, fluids and gels offer no microbial barrier between thepatient and the probe transducer; thus, latex rubber or syntheticelastomer probe covers must be applied over the probe transducer, toprevent transmission of microorganisms to the patient. Often, two layersof couplant, one inside and one outside the probe cover, are required toprovide ultrasound acoustic coupling between transducer and the patient.This potential infection concern is readily apparent when the transduceris used for imaging during needle biopsy or aspiration, or inside thebody during surgery in direct organ, tissue and blood contact. Ofgrowing importance is the protection from infection by skin transmissionto patients who are immune compromised by disease, organ replacement,immune system modification, chemotherapy or radiation treatments.Ultrasonic gel has been observed to have many microbial and clinicalchallenges as evidenced by many clinical papers. In addition, the USFood and Drug Administration has issued several warnings about microbialcontaminants related to the ultrasound gel. It has also resulted inclosing of a company. Furthermore, there are several papers publisheddescribing the impact of microbial issues related to the ultrasound gel.

Fluids or thickened water-based gels typically used in medicalultrasound, similarly described as in U.S. Pat. No. 4,002,221, arecomprised of chemical compounds such as acrylic polymers, carboxy alkylcellulose, hydroxyethylcellulose, carboxy polymethylene, organic acids,alkali metal salts, parabens and other germicidal and fungicidal agents,and surfactants. Such chemicals are not approved or suitable for use inapplications where they may be carried into the body, such as duringbiopsy, intra-operative procedures, or when the transducer is placedinside a body orifice. In instances where sterile latex rubber orsynthetic covers containing thickened ultrasound coupling gels are usedin surgery, tearing, cutting, or rupture of the cover results in thetissue incompatible ultrasound coupling gel spilling into the bodycavity. During ultrasound guided needle biopsy, aspiration, intracavityand intraoperative procedures, sterile covers produced from latex,polyurethane, polypropylene and other polymers, such as described inU.S. Pat. No. 4,593,699 to Poncy et al., U.S. Pat. No. 5,259,383 toHolstein et al. and U.S. Pat. No. 5,676,159 to Navis, are used with suchtissue incompatible gel chemicals. A puncturing needle can carry suchchemicals into the body, such as into the breast or into amniotic fluid,since gels are present on the skin of the patient at the point of needleinsertion, as well as between the transducer and the probe cover toaccomplish ultrasound acoustic coupling. Thus, as a puncturing needlepasses through the gel on the skin of the patient, minute quantities ofthe gel may be carried into the underlying tissue and the body cavitythereby introducing a likely tissue-incompatible substance into thepatient. It is apparent that this gel may also harbor bacterialorganisms from manufacturing or transfer from local sources duringclinical use which can then also be transferred into the body.

In addition, many practitioners also have difficulty with consistency ofapplication. It is difficult for many practitioners to apply enough gelwithin a probe cover to prevent air pockets, to remain thick enough andevenly applied between the probe and cover throughout the examinationwithout ‘spilling around’ edges of the probe, and without causing uneven‘wrinkles’ or curvatures of the cover which causes air pockets outsidethe probe cover. This increases procedure time and results in suboptimalvisualization of underlying structures and interferes with the qualityof examination or procedure.

Therefore, improved methods and devices are desired to reliably andsafely provide maximal transmission of acoustic energy during ultrasoundimaging while reducing fundamental disadvantages associated with theconventional use of ultrasound couplants. At least some of theseobjectives will be met by the present invention.

SUMMARY OF THE INVENTION

The present invention generally relates to medical devices, systems andmethods for ultrasound technology. In particular, the present inventiongenerally relates to devices, systems and methods for creating anuninterrupted pathway of acoustic conductance from the faceplate of anultrasonic probe to the surface of the body without externally appliedcouplant, such as ultrasonic gel.

In a first aspect of the present invention, a device is provided forcoupling with at least a faceplate of an ultrasound probe for ultrasoundtransmission through a surface of a body. In some embodiments, thedevice comprises an ultrashield comprising a couplant layer having acouplant, and a body contact layer adjacent the couplant layer, the bodycontact layer having a plurality of openings which allow controlledrelease of the couplant from the couplant layer through the openings tothe surface of the body, wherein the ultrashield provides ultrasoundwave transmission from the faceplate of the ultrasound probe to thesurface of the body with minimal to no attenuation. Typically, the bodycontact layer is configured to glide over the surface of the body withminimal friction. Thus, in some embodiments, the body contact layercomprises a material having a low coefficient of friction. In someembodiments, the body contact layer has a coefficient of friction lessthan or equal to natural human skin. For example, in some embodiments,the body contact layer has a coefficient of friction less than or equalto 0.5. Optionally, in some embodiments, the body contact layer has acoefficient of friction less than or equal to 0.1. Example materialsinclude polyester, polyvinylidene fluoride or polytetrafluoroethylene.

In some embodiments, the couplant comprises water. In some embodiments,the couplant layer comprises ultrasonic gel. In some embodiments, thecouplant layer comprises a hydrogel. In some embodiments, the couplantlayer comprises a thermoplastic elastomer, a polymer matrix or acollagen material. In some embodiments, the couplant layer comprises apouch filled with the couplant. In some embodiments, the couplant isselected from the group consisting of water, silicone oil, silicone gel,propylene glycol, glycerin, a corrosion inhibitor, carboxypolymethylene, cellulose, amino alcohol, a surfactant, a preservative,and combinations thereof.

In some embodiments, each opening of the plurality of openings is in therange of up to 10 microns.

In some embodiments, the body contact layer is sufficiently flexible toallow compression of the couplant layer. Optionally, the body contactlayer is sufficiently stretchable to move axially so as to conform tothe surface of the body as the probe glides thereover.

In some embodiments, the device further comprises a probe contact layerconfigured to mate with the couplant layer and adhere to the ultrasoundprobe. In other embodiments, the device further comprises a probe coverhaving at least a bottom surface configured to cover the faceplate ofthe ultrasound probe, wherein the ultrashield is disposed along thebottom surface so that the bottom surface and ultrashield provideultrasound wave transmission from the faceplate of the ultrasound probeto the surface of the body with minimal to no attenuation. In someinstances, the ultrashield is integral with the probe cover. In otherinstances, the ultrashield further comprises a probe contact layerconfigured to mate with the couplant layer and adhere to the bottomsurface of the probe cover. Optionally, the device may further comprisea removable protective pouch extending over the ultrashield, wherein thepouch resists loss of couplant from the couplant layer.

In some embodiments, the device further comprises a replenishmentmechanism configured to replenish the couplant layer with couplant. Insome instances, at least a portion of the replenishment mechanism ispre-filled with couplant.

In some embodiments, the ultrashield has a thickness in the range of 0.1to 0.3 inches, more particularly 0.110 to 0.220 inches.

It may be appreciated that the ultrashield creates an uninterruptedpathway of acoustic conductance from the faceplate of the probe to thesurface of the body without externally applied couplant to the probe orthe surface of the body when the probe is applied to the surface of thebody for ultrasound transmission therethrough.

In a second aspect of the present invention, a probe cover is providedfor encasing an ultrasound probe during ultrasound transmission througha surface of a body, such as for ultrasound imaging. In someembodiments, the probe cover comprises a bottom surface configured tocover a faceplate of the ultrasound probe; and an ultrashield disposedalong the bottom surface, the ultrashield comprising a couplant layerhaving a couplant, and a body contact layer adjacent the couplant layer,the body contact layer having a plurality of openings which allowcontrolled release of the couplant from the couplant layer through theopenings to the surface of the body, wherein the bottom surface andultrashield provide ultrasound wave transmission from the faceplate ofthe ultrasound probe to the surface of the body with minimal to noattenuation. In some embodiments, the couplant layer comprises ahydrogel. In some embodiments, the body contact layer is configured toglide over the surface of the body with minimal friction. In someembodiments, the body contact layer comprises a material having a lowcoefficient of friction. In some embodiments, the body contact layer hasa coefficient of friction less than or equal to natural human skin. Forexample, in some embodiments, the body contact layer has a coefficientof friction less than or equal to 0.5. Optionally, the body contactlayer may have a coefficient of friction less than or equal to 0.1.Example materials include polyester, polyvinylidene fluoride andpolytetrafluoroethylene.

In some embodiments, the couplant comprises water. In some embodiments,the couplant layer comprises a hydrogel. In some embodiments, thecouplant layer comprises a thermoplastic elastomer, a polymer matrix ora collagen material. In some embodiments, the couplant layer comprises apouch filled with the couplant. In some embodiments, the couplant isselected from the group consisting of water, silicone oil, silicone gel,propylene glycol, glycerin, a corrosion inhibitor, carboxypolymethylene, cellulose, amino alcohol, a surfactant, a preservative,and combinations thereof.

In some embodiments, each opening of the plurality of openings is in therange of up to 10 microns.

In some embodiments, the body contact layer is sufficiently flexible toallow compression of the couplant layer. Optionally, the body contactlayer is sufficiently stretchable to move axially so as to conform tothe surface of the body as the probe glides thereover.

In some embodiments, the ultrashield further comprises a probe contactlayer configured to mate with the couplant layer and adhere to the probecover. In other embodiments, the ultrashield is integral with the probecover. Optionally, the probe cover may further comprise a removableprotective pouch extending over the ultrashield, wherein the pouchresists loss of couplant from the couplant layer.

In some embodiments, the probe cover further comprises a replenishmentmechanism configured to replenish the couplant layer with couplant. Insome instances, at least a portion of the replenishment mechanism ispre-filled with couplant.

In some embodiments, the ultrashield has a thickness in the range of 0.1to 0.3 inches, more particularly 0.110 to 0.220 inches.

It may be appreciated that the probe cover creates an uninterruptedpathway of acoustic conductance from the faceplate of the probe to thesurface of the body without externally applied couplant to the probe orthe probe cover when the probe is applied to the surface of the body forultrasound transmission therethrough.

In another aspect of the present invention, a method of transmittingultrasound through a surface of a body with an ultrasound probe isprovided. In some embodiments, the method comprises covering a faceplateof the ultrasound probe with an ultrashield, wherein the ultrashieldcomprises a couplant layer having a couplant, and a body contact layeradjacent the couplant layer, the body contact layer having a pluralityof openings which allow controlled release of the couplant from thecouplant layer through the openings to the surface of the body. Suchmethods further include contacting the ultrashield to the surface of thebody so that the ultrashield creates an uninterrupted pathway ofacoustic conductance from the faceplate of the probe to the surface ofthe body without externally applied couplant to the probe or the surfaceof the body, and transmitting ultrasound through the surface of the bodywith the faceplate of the ultrasound probe.

In some embodiments, when the ultrashield comprises a probe contactlayer adjacent to the couplant layer, covering the faceplate comprisesadhering the probe contact layer to the faceplate of the ultrasoundprobe. In some embodiments, the ultrashield is carried by a probe cover,and covering the faceplate comprises covering the faceplate with theprobe cover so that the ultrashield covers the faceplate of theultrasound probe.

In some embodiments, the ultrashield is covered by a protective pouchand the method further comprising removing the protective pouch prior tocontacting the ultrashield to the surface of the body. In someinstances, the method further comprises replenishing the couplant.Optionally, replenishing the couplant comprises activating areplenishment system.

It may be appreciated that in some embodiments, transmitting ultrasoundcomprises imaging through the surface of the body.

These and other embodiments are described in further detail in thefollowing description related to the appended drawing figures.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 illustrates an embodiment of an ultrashield and a probe to whichthe ultrashield is affixable.

FIG. 2 illustrates an ultrashield sized and configured so that portionsof its exterior edge wrap around the probe.

FIGS. 3A-3B illustrate an embodiment of a probe cover having anultrashield.

FIG. 4 illustrates an embodiment of an ultrashield in an expanded view.

FIG. 5 illustrates the ultrashield embodiment of FIG. 4 in an unexpandedview.

FIG. 6 illustrates an embodiment of a couplant layer comprising acouplant pouch.

FIGS. 7-8 schematically illustrate an embodiment of an ultrashieldwherein the couplant layer comprises a couplant material.

FIGS. 9-10 schematically illustrate an embodiment of an ultrashieldwherein the couplant layer comprises a couplant pouch.

FIG. 11 schematically illustrates an embodiment of an ultrashieldwherein the couplant layer comprises a thermoplastic elastomer.

FIG. 12 schematically illustrates an embodiment of an ultrashieldwherein the probe contact layer has a window through which the couplantlayer extends.

FIGS. 13-14 schematic illustrate embodiments of a probe cover having anultrashield.

FIG. 15 illustrates an embodiment of an ultrashield between packaginglayers in an expanded view.

FIG. 16 illustrates an embodiment of an ultrashield in packaging.

FIG. 17 illustrates an embodiment of an ultrashield which is integralwith a probe cover and further comprising a protective pouch.

FIGS. 18-19 illustrate an example probe covers having ultrashields andreplenishment mechanisms.

FIGS. 20A-20B illustrate example probe having a curved faceplate and anultrashield having a corresponding shape.

FIGS. 21A-21B illustrate an example probe having a smaller curvedfaceplate and an ultrashield having a corresponding shape.

FIGS. 22A-22B illustrate example probe having a round or circularfaceplate and an ultrashield having a corresponding shape.

FIGS. 23A-23B illustrate example probe having a square faceplate and anultrashield having a corresponding shape.

FIGS. 24A-24B illustrate example probe having a rectangular faceplatedisposed along a side of an elongate probe housing and an ultrashieldhaving a corresponding shape.

DETAILED DESCRIPTION OF THE INVENTION

Specific embodiments of the disclosed devices and methods will now bedescribed with reference to the drawings.

Devices and methods are provided for specific use with ultrasoundmachines to enable a clinician or a technician to use a conventionalultrasound probe, such as to generate an ultrasonic image, without theneed for external ultrasonic gel or similar couplant. In particular, anultrashield is provided for use with a conventional ultrasound probethat eliminates the need for additional ultrasonic couplants, such asgels. The ultrashield is a cover or shield which is positioned over thefaceplate of an ultrasound probe, either alone or in conjunction with aprobe cover. FIG. 1 illustrates an embodiment of an ultrashield 10 whichis sized and configured to affix to the faceplate 12 of an ultrasoundprobe 14, as indicated by arrows. Typically, the ultrashield 10 is sizedand configured so that portions of its exterior edge wrap around theprobe 14, beyond the faceplate 12, so as to ensure a complete seal, asillustrated in FIG. 2 . The ultrasound probe 14 comprises a housing 16which contains the piezoelectric crystal, electrodes, and acousticinsulator. The housing 16 is connected with a coaxial cable 18 whichextends to the ultrasound machine (not shown). The ultrasound waves aretransmitted from the piezoelectric crystal through the faceplate 12, tothe body of the patient. By affixing the ultrashield 10 to the faceplate12, the ultrasound waves pass directly through the ultrashield 10,without introducing an air barrier or a significant difference inimpedance. Likewise, when the probe 14 is in use, the ultrashield 10contacts the surface of the patient, again without introducing a barrieror a significant difference in impedance. Particular features of theultrashield 10 allow its use without a traditional external gel couplantas will be described herein.

FIGS. 3A-3B illustrate an embodiment of a probe cover 20 having anultrashield 10. Such a probe cover 20 is typically used in sterileconditions in an operating room. The probe cover 20 allows the use ofthe probe 14 in scanning and needle guided procedures for body surface,endocavity and intra-operative diagnostic ultrasound procedures, whilehelping to prevent transfer of microorganisms, body fluids andparticulate material to the patient and healthcare worker during reuseof the probe 14. The probe cover 20 provides an extremely important needwhich is to provide a removable barrier between the probe 14 and theindividual patient which will prevent infectious particles from beingtransmitted to different patients due to inadequate cleanings of theprobe between uses. Such a barrier between the patient and the probe 14(that is exchanged between probe uses) is particularly important formany probes 14 which have crevices and contours that have been found tobe very difficult to definitively clean, leading to an increased risk ofspreading infectious particles.

In this embodiment, the probe cover 20 has an oblong, rectangular shape,as illustrated in FIG. 3A, with a bottom surface 22 having a rectangularshape for use with a probe having a rectangular shaped faceplate 12.However, it may be appreciated that such probe covers 20 may havevarious shapes and forms for accommodating various types of probes. Inthis embodiment, the ultrashield 10 is disposed along the bottom surface22. The cover 20 is then positioned over the probe 20. FIG. 3Billustrates the probe cover 20 of FIG. 3A positioned on a probe 14.Here, the ultrashield 10 is aligned with the faceplate 12 of the probe14 and the cover 20 is pulled up tightly around the probe, so as toremove any wrinkles, taking care to avoid puncturing the cover. Thecover 20 may be secured to the cable 18 with bands 24. The use of such aspecialized probe cover 20 eliminates the need for application of a gelcouplant inside the cover and/or on the faceplate. This savespreparation time, reduces damage to the probe, eliminates thepossibility of puncture and leakage of gel, reduces clean up time andeliminates the possibility of cross-contamination due to gel residuetrapped in the probe 14.

As mentioned, when the clinician starts ultrasonic imaging, the probe 14is able to visualize through the ultrashield 10 and it moves along withthe probe 14. The separate gel couplant is not required due to thespecialized properties of the ultrashield 10 that provide ultrasonicconductivity along with ease of gliding over the patient skin or bodysurface. Such specialized properties are provided by various layers thatmake up the ultrashield 10. These layers are also echogenic andfacilitate transmission of ultrasonic waves with minimal or no loss.FIG. 4 illustrates an embodiment of an ultrashield 10 in an expandedview revealing various layers. In this embodiment, the layers include aprobe contact layer 30, an intermediate sandwich layer or couplant layer32, and an outer surface body contact layer 34. These layers will bedescribed in more detail below. FIG. 5 illustrates the ultrashield 10embodiment of FIG. 4 in an unexpanded view wherein the layers 30, 32, 34are stacked and adhered together to form a single multi-layered sheet.As shown, the ultrashield 10 has a thin, compact design which is easilypackaged, handled and applied to the head of a probe 14. It may beappreciated that the ultrashield 10 may take a variety of forms. In someembodiments, the ultrashield 10 includes all of the layers depicted inFIGS. 4-5 , however the invention is not so limited. For example, insome embodiments, aspects of a particular layer are provided by anotherlayer of the ultrashield 10 or the probe cover 20.

Probe Contact Layer

The probe contact layer 30 provides an integrated polymeric surface thatconnects with the probe 14 and gives a connection that is substantiallyfree of any air or vacuum. This ensures that the ultrashield 10 will beintegral to the probe 14 as a ‘seamless’ surface. The probe contactlayer 30 is typically comprised of a flexible film, such as flexiblepolymer film. In some embodiments, the film includes a rigid layer, suchas a rigid center layer, to provide additional structure. The centralrigid layer typically resides along the portion of the probe contactlayer 30 that covers the faceplate 12 of the probe 14, allowing a moreflexible portion of the contact layer 30 (such as disposed around therigid center layer) to bend around the probe 14.

In some embodiments, the contact layer 30 has a thickness in the rangeof 0.010 to 0.060 inches, more particularly 0.030 to 0.060 inches.Similarly, in some embodiments, the contact layer 30 has a thickness ofless than or equal to 0.060 inches, less than or equal to 0.050 inches,less than or equal to 0.040 inches, or less than or equal to 0.020inches. In some embodiments, the contact layer 30 is comprised of quartzor a polymer such as polyethylene, polyurethane, polypropylene,polyester, ethylene vinyl acetate, polyvinyl chloride, or the like. Ineach of these instances, the layer 30 has a low level of attenuationco-efficient and shall provide minimal or no diminishment of ultrasoundwave transmission.

Typically, the probe contact layer 30 includes an adhesive 31 on atleast one side of the contact layer 30. The adhesive 31 allows theultrashield 10 to be affixed to the probe 14, such as the faceplate 12of the probe 14 and optionally the housing 16. This creates an airlessconnection between the ultrashield 10 and the probe 14. In someembodiments, the probe contact layer 30 includes an adhesive 31 toadhere the couplant layer 32 and/or the outer surface body contact layer34 thereto.

Typically, the adhesive 31 has a very fine thickness, such as 0.001 to0.005 inches, more particularly 0.002 to 0.003 inches. Example adhesives31 include epoxy, polyurethane, cyanoacrylate and acrylic polymers, toname a few. In some embodiments, the adhesive 31 comprises a pressureadhesive wherein upon application of pressure the contact layer 30adheres to the probe 14 and when it is pulled for removal it leavesbehind negligible or no residue. It may be appreciated that the adhesive31 shall provide minimal or no diminishment of ultrasound wavetransmission as well.

Couplant Layer

In this embodiment, the couplant layer 32 comprises a couplant material33 such as a hydrogel, collagen material, polymer matrix and/orthermoplastic elastomer containing a couplant. The couplant material 33has a very low acoustic attenuation coefficient, such as 0.05 dB/cm/MHzor less at a frequency of 1540 MHz (human tissue), so that it transmitsthe ultrasonic wave with minimal to no loss of energy. The lower theattenuation coefficient, the better is the transmission of ultrasonicwave through the material. In preferred embodiments, the couplant withinthe couplant material 33 comprises water which has the lowestattenuation coefficient. However, other couplants may be used such asglycerin, silicone oil, silicone gel or other ultrasound gels, such thathave very low attenuation coefficients. The couplant layer 32 typicallyhas a thickness in the range of approximately 0.060 to 0.150 inches,more particularly 0.010 to 0.040 inches. Likewise, the couplant layer 32is typically flexible or pliable by means of a low durometer profile,such as a durometer between 10-20 Shore A-2.

In some embodiments, the couplant material 33 is comprised of a hydrogelmaterial which retains water in a colloidal condition for extendedperiods of time. Hydrogels are polymer networks extensively swollen withwater. Hydrogels are made of crosslinked water-soluble polymers. Becauseof the crosslinks, hydrogels can absorb water and get swollen, butcannot be dissolved. In particular, the ability of hydrogels to absorbwater arises from hydrophilic functional groups attached to thepolymeric backbone, while their resistance to dissolution arises fromcross-links between network chains. Through many intricatecustomizations, a hydrogel can be sensitive or responsive to thefluctuations in its external environment, such as, temperature, pH,ionic strength, electric stimulus, etc Hydrogels inherently possess adegree of flexibility very similar to natural tissue due to their largewater content. Such flexibility, along with the ability to be formedinto sheets and the ability to retain water, make hydrogels a desiredcouplant layer 32.

In some instances, the couplant layer 32 is inherently adhesive. Forexample, couplant materials 33 having greater than 95% water aretypically self-adhesive. In such instances, the layer 32 may adhere tothe probe contact layer 30 and/or outer surface body contact layer 34without additional adhesives 31.

In other embodiments, the couplant layer 32 comprises a couplant pouch35 containing a couplant 37, as illustrated in FIG. 6 . In suchembodiments, the couplant pouch 35 has similar dimensions or volume as acouplant material 33 with a thickness of approximately 0.030 inches (30mil) for fill volume. The probe contact layer 30 is typically comprisedof a flexible polymer such as polyethylene, polyurethane, polypropylene,polyester, ethylene vinyl acetate, polyvinyl chloride, or the like. Ineach of these instances, the pouch 35 has a low level of attenuationco-efficient and shall provide minimal or no diminishment of ultrasoundwave transmission.

The couplant pouch 35 is filled with one or more couplants 37 and/orother materials, such as preservatives or additives. For example, insome embodiments the couplant pouch 35 is filled with one or more of thefollowing:

-   -   Water (such as 7732-18-5)    -   Silicone oil    -   Silicone gel    -   Propylene Glycol (such as 57-55-6)    -   Ultrasound gel    -   Glycerin (such as 56-81-5)    -   Corrosion Inhibitors    -   Carboxy Polymethylene (such as 9003-01-4)    -   Cellulose (such as 9004-62-0)    -   Amino Alcohol    -   Surfactant    -   Preservative (such as 78491-02-8)

It may be appreciated that in some embodiments, the couplant layer 32 iscomprised of conventional ultrasound gel or lotion. Thus, in someembodiments, the couplant layer 32 is comprised of a thin layer ofconventional ultrasound gel itself. Alternatively, in other embodiments,the couplant layer 32 is comprised of a couplant material 33 whichincludes conventional ultrasound gel or lotion, or the couplant layer 32is comprised of a couplant pouch 35 which includes conventionalultrasound gel or lotion.

In each of the embodiments described herein, the couplant layer 32 isselected for its favorable ultrasonic wave transmission ability. Sincethe layer 32 does not come in direct contact with the tissue or skin ofthe patient, the choice of couplant layer 32, material 33 or pouch 35 isnot limited by other parameters, such as wearability, coefficient offriction, or adhesion. Therefore, the couplant layer 32, material 33 orpouch 35 providing superior ultrasonic transmission ability may be used.Likewise, in each of these embodiments, the couplant layer 32 forms anair pocket-free layer to provide superior ultrasonic without the needfor additional external couplants such as conventional gels.

Outer Surface Body Contact Layer

The outer surface body contact layer 34 is configured to glide easilyover the tissue or skin of the patient's body against which it is incontact. Thus, the body contact layer 34 is the outermost surface of theprobe 14 when the ultrashield 10 is mounted thereon. Such glide-abilityis due to various characteristics of the layer 34. To begin, in someembodiments, the body contact layer 34 is comprised of a material havinga low coefficient of friction. The coefficient of friction is the ratiobetween the force of sliding friction and the normal force. In someembodiments, the body contact layer 34 has a coefficient of frictionthat is less than or equal to the coefficient of friction of naturalhuman skin, such as dry skin unwetted by emollients, lotions orpetrolatums. The coefficient of friction for natural skin various acrossthe human body. The palm of the hand has the highest coefficient offriction on the body, in the range of approximately 0.4-0.84(0.62+/−0.22). However, the average coefficient of friction for naturalskin is in the range of approximately 0.31-0.61 (0.46+/−0.15). Thus, insome embodiments, the body contact layer 34 has a coefficient offriction that is less than or equal to the coefficient of friction ofthe palm of the hand (less than 0.84, less than 0.62 or less than 0.4,to name a few). Likewise, in some embodiments, the body contact layer 34has a coefficient of friction that is less than the average coefficientof friction of natural skin (less than 0.61, less than 0.046 or lessthan 0.31, to name a few). Thus, in some embodiments, the body contactlayer 34 has a coefficient of friction of less than or equal to 0.5. Inpreferred embodiments, the body contact layer 34 has a coefficient offriction that is less than or equal to 0.1.

This is in contrast to a typical hydrogel which alone typically has acoefficient of friction that is greater than 1. In some embodiments, thebody contact layer 34 is comprised of a film having a low coefficient offriction, such as polyester, polyvinylidene fluoride (PVDF) andpolytetrafluoroethylene (PTFE) or TEFLON™. It may be appreciated that insome embodiments, the contact layer 34 is plasma treated or coated witha fine film of biocompatible material to reduce friction. In someembodiments, the body contact layer 34 has a thickness in the range ofapproximately 0.010 to 0.070 inches, more particularly 0.020 to 0.060inches.

The outer surface body contact layer 34 has controlled openings, such assubmicron or micron sized openings (e.g. 1 nm, 0.05 μm to 2.0 μm), whichboth assist in retention of couplant within the adjacent couplant layer32 and allow a slow release of the couplant from the couplant layer 32to the skin or body surface. Thus, the body contact layer 34 can beconsidered as a filter itself or it may be comprised of such a filter.In such embodiments, the body contact layer 34 may comprise openings ofuniform or varying sizes, including 0.2-2.0 micron, 0.5-5 micron, 1micron, 2 micron, 3 micron, 4 micron, 5, micron, up to 10 micron, 10micron, to name a few. The release of couplant creates an uninterruptedpathway of acoustic conductance from the probe 14 to the skin or bodysurface of the patient. In other words, the release of couplant to thebody surface causes the body surface to be acoustically conductive withthe ultrasound. In many instances, the couplant is water which isnon-obtrusive to the patient and easily absorbed, evaporated or wipedaway after the procedure. Likewise, the body contact layer 34 istypically hydrophilic so as to be acoustically conductive as well.

In some embodiments, the body contact layer 34 creates a stretchablesurface that moves axially as the probe 14 is moved over the tissue orskin of the patient so as to mimic the conventional gel function withoutcompromising the body contact layer 34 and the body interface. In someembodiments, the body contact layer 34 is comprised of a membrane withat least 50% elongation to allow the probe 14 to adhere to the skin ofbody surface.

In some embodiments, the body contact layer 34 is sufficiently flexibleso as to allow the compression of the sandwich layer 32. It may beappreciated that many liquids, such as water, are essentiallyincompressible. Therefore, when the sandwich layer 32 includes one ormore liquids, the contact layer 34 is expandable to allow for shiftingof the liquid due to compression of the sandwich layer 32 by the probe14.

In some embodiments, the body contact layer 34 creates a breathingsurface so that any potential air trapped between the skin and thecontact layer 34 is moved away from the contact layer 34. In someinstances, couplant, such as water, exiting the body contact layer 34pushes any trapped air outward, creating a continuous ultrasonicconnection.

It may be appreciated that although the body contact layer 34 controlselution of couplant from the couplant layer 32, resisting quickemptying, it is possible for the couplant to eventually empty. In suchinstances, the couplant layer 32 may be re-filled with couplant throughthe body contact layer 34. For example, the body contact layer 34 may beplaced into couplant to allow the couplant to absorb through thecontrolled openings of the layer 34 and into the couplant layer 32 forreplenishment.

It may be appreciated that if the couplant layer 32 was in directcontact with the patient's skin, it would be very difficult to glide.Hydrogels and other polymer matrices are characteristically sticky andtherefore do not glide easily if at all over skin or various bodysurfaces. The couplant layer 32 alone would also flow the couplant outonto the patient's skin without any control and may dispense all thecouplant immediately, thereby rendering its effectiveness to be for avery short duration.

In some embodiments, the couplant layer 32 comprises a couplant material33 having a rectangular shape, such as approximately 2.5 inches (63.50mm) long and 0.5 inches (12.70 mm) wide, and an adhesive sheet 35 havinga larger rectangular shape, such as approximately 3.25 inches (82.55 mm)long and 1.25 inches (31.75 mm) wide. In some embodiments, the bodycontact layer 34 also has a rectangular shape, such as approximately 3inches (76.20 mm) long and 1.0 inch (25.40 mm) wide. In someembodiments, the probe contact layer 30 also has a rectangular shape,such as approximately 3.39 inches (86 mm) long and 1.38 inches (35 mm)wide. It may be appreciated that such dimensions are exemplary for aconventional probe having a rectangular faceplate. Ultrashields havingother dimensions may be used, particularly for other shaped probes.

FIG. 7 schematically illustrates an embodiment of an ultrashield 10. Inthis embodiment, the ultrashield 10 comprises a probe contact layer 30,an couplant layer 32 and an outer surface body contact layer 34. In thisillustration, the body contact layer 34 is shown curving upwards so asto affix to a probe 14 as previously illustrated in FIG. 2 . Thus, inthis embodiment, the probe contact layer 30 is configured to extendfurther along the probe 14 than simply along the faceplate 12. In thisembodiment, portions of the probe contact layer 30 form side walls 30 a,30 b which are configured to extend up and along the housing 16 of theprobe 14. Thus, in some embodiments the probe contact layer 30 includesadhesive 31 along the inner surface of the side walls 30 a, 30 b so asto adhere the side walls 30 a, 30 b, and therefore the ultrashield 10,to the probe 14. In this embodiment, the ultrashield 10 further includesan couplant layer 32 comprising a couplant material 33. Likewise, thisembodiment includes a body surface layer 34 configured to contact thepatient's skin. The body surface layer 34 controls the amount and rateof liquid couplant dispensed. Since the body surface layer 34 has a lowco-efficient of friction, it glides easily on the patient skin.Referring to FIG. 8 , in some embodiments, the ultrashield 10 alsoincludes an adhesive 31′ disposed along the probe contact layer 30 at alocation so as to adhere the probe contact layer 30 to the faceplate 12of the probe 14. It may be appreciated that the adhesive 31, 31′ maycover a variety of surfaces of the probe contact layer 30, including allsurfaces of the probe contact layer 30, to assist in adhering theultrashield 10 to the probe 14.

FIG. 9 schematically illustrates another embodiment of an ultrashield10. In this embodiment, the probe contact layer 30 also has side walls30 a, 30 b which are configured to extend up and along the housing 16 ofthe probe 14. Thus, the probe contact layer 30 includes adhesive 31 atleast along the inner surface of the side walls 30 a, 30 b so as toadhere the side walls 30 a, 30 b, and therefore the ultrashield 10, tothe probe 14. In this embodiment, the ultrashield 10 further includes ancouplant layer 32 comprising a couplant pouch 35 containing a couplant37, such as water or glycerin. Likewise, this embodiment includes a bodysurface layer 34 configured to contact the patient's skin. Again, thebody surface layer 34 controls the amount of and rate of liquid couplant37 release. Since the body surface layer 34 has a low co-efficient offriction, it glides easily on the patient skin. Referring to FIG. 10 ,in some embodiments, the ultrashield 10 also includes an adhesive 31′disposed along the probe contact layer 30 at a location so as to adherethe probe contact layer 30 to the faceplate 12 of the probe 14. It maybe appreciated that the adhesive 31, 31′ may cover a variety of surfacesof the probe contact layer 30, including all surfaces of the probecontact layer 30, to assist in adhering the ultrashield 10 to the probe14.

FIG. 11 schematically illustrates another embodiment of an ultrashield10. In this embodiment, the probe contact layer 30 again has portionsacting as side walls 30 a, 30 b which are configured to extend up andalong the housing 16 of the probe 14. Thus, the probe contact layer 30includes adhesive 31 along the inner surface of the side walls 30 a, 30b so as to adhere the side walls 30 a, 30 b, and therefore theultrashield 10, to the probe 14. In this embodiment, the ultrashield 10further includes an couplant layer 32 comprising a thermoplasticelastomer having a couplant. Likewise, this embodiment includes a bodysurface layer 34 configured to contact the patient's skin. Again, thebody surface layer 34 controls the amount and rate of liquid couplantdispensed. Since the body surface layer 34 has a low co-efficient offriction, it glides easily on the patient skin.

FIG. 12 schematically illustrates another embodiment of an ultrashield10. In this embodiment, the probe contact layer 30 again has portionsacting as side walls 30 a, 30 b which are configured to extend up andalong the housing 16 of the probe 14. Thus, in this embodiment, theprobe contact layer 30 includes adhesive 31 at least along the innersurface of the side walls 30 a, 30 b so as to adhere the side walls 30a, 30 b, and therefore the ultrashield 10, to the probe 14. In thisembodiment, the probe contact layer 30 has a window wherein a portion ofthe contact layer 30 is replaced with the couplant layer 32. Thus, thecouplant layer 32 is disposed so as to directly contact the faceplate 12of the probe 14 when the ultrashield 10 is positioned thereon. To ensureadequate adhesion of the couplant layer 32 to the probe 14, particularlythe faceplate 12, an adhesive 31′ is disposed along the couplant layer32 to desirably adhere the couplant layer 32 to the faceplate 12. Asshown, the body surface layer 34 configured to adhere to the couplantlayer 32 and the probe contact layer 30. Again, the body surface layer34 also controls the amount and rate of liquid couplant dispensed to thepatient's skin. Since the body surface layer 34 has a low co-efficientof friction, it glides easily on the patient skin.

As mentioned previously in relation to FIGS. 3A-3B, in some embodimentsthe ultrashield 10 is integral with a probe cover 20. The probe cover 20provides a removable barrier between the probe 14 and the individualpatient which will prevent infectious particles from being transmittedto different patients due to inadequate cleanings of the probe betweenuses. As mentioned, such a barrier between the patient and the probe 14(that is exchanged between probe uses) is particularly important formany probes 14 which have crevices and contours that have been found tobe very difficult to definitively clean, leading to an increased risk ofspreading infectious particles.

FIG. 13 is a schematic illustration of an embodiment of a probe cover 20having an ultrashield 10. In this embodiment, the ultrashield 10comprises an couplant layer 32 and a body surface layer 34 which arebuilt into a bottom portion or surface of the probe cover 20. In thisembodiment, the couplant layer 32 comprises a hydrogel which capturesthe couplant. The skin contact layer 34 comprises a filtration membranethat controls the amount and rate of liquid being delivered. It also haslow co-efficient of friction and glides easily on the patient skin. Itmay be appreciated that in this embodiment, couplant layer 32 isdirectly adjacent the probe cover 20, wherein a separate probe contactlayer 30 is not present. As such the probe cover 20 acts as the probecontact layer 30. The probe cover 20 is configured to extend over aprobe 14 so that the ultrashield 10 is aligned with the faceplate 12 ofthe probe 14. Typically, the probe cover 20 includes adhesive 31 along aportion of its inner walls or surfaces to hold the cover 20 snugly tothe probe 14. Referring to FIG. 14 , in some embodiments, the probecover 20 also includes an adhesive 31′ disposed along the inside of theprobe cover 20 at a location so as to adhere the probe cover 20 directlyto the faceplate 12 of the probe 14. It may be appreciated that theadhesive 31, 31′ may cover a variety of surfaces of the probe cover 20to assist in adhering the ultrashield 10 to the probe 14.

It may be appreciated that in some embodiments the ultrashield 10 isseparate from the probe cover 20 and can be adhered to a surface of theprobe cover 20 for use. Thus, rather than adhering the probe contactlayer 30 directly to the probe 14, the probe contact layer 30 is adheredto the probe cover 20. This allows the user to utilize the ultrashield10 with any probe cover 20 or similar device.

Packaging

The ultrashield 10 is packaged so as to reduce or eliminate evaporationof couplant from the couplant layer 32. Thus, such packaging will assistin increasing shelf-life and ensure that the ultrashield 10 is desirablyfunctioning when removed from the packaging for use. In someembodiments, as illustrated in FIG. 15 , the ultrashield 10 is disposedbetween packaging layers 50 a, 50 b. The packaging layers 50 a, 50 b aresized and configured to encase the ultrashield 10. In most embodiments,the probe contact layer 30 has an adhesive 31 which adheres the probecontact layer to the packaging layer 50 b. In some embodiments, when thepackaging layer 50 b is removed for use, the same adhesive 31 is thenused to adhere the ultrashield 10 to the probe 14. The other packaginglayer 50 a is adhered to the body surface layer 34 with an adhesivewhich remains on the packaging layer 50 a when the packaging layer 50 ais removed. Thus, the body surface layer 34 is free of adhesive whenready for use.

FIG. 16 illustrates an embodiment of the ultrashield 10 and packaging inan unexpanded view. Here, the layers 30, 32, 34 are stacked and adheredtogether to form a single multi-layered ultrashield 10. The ultrashield10 is held between packaging layers 50 a, 50 b. And, the packaginglayers 50 a, 50 b are further held within a packaging pouch or sleeve60. The packaging sleeve 60 protects the packaged ultrashield duringtransport and storage. The packaging sleeve 60 is comprised of amaterial, such as aluminum, which reduces water vapor transmission orloss of couplant. In some embodiments, the packaging sleeve 60 allowsminimal to no transmission of water vapor or couplant. This ensures thepresence of moisture in the ultrashield 10 when the packaging sleeve 60is opened for use of the ultrashield 10. It may be appreciated that,alternatively or in addition, the packaging layers 50 a, 50 b may becomprised of a material which reduces water vapor transmission or lossof couplant.

FIG. 17 illustrates an embodiment of an ultrashield 10 which is integralwith a probe cover 20, further comprising a protective pouch 62 whichextends over the ultrashield 10 to protect the ultrashield 10 prior touse. In some embodiments, the protective pouch 62 encases theultrashield 10 so as to resist or prevent water vapor loss or loss ofcouplant from the couplant layer 32. This provides an extendedshelf-life and ensures that the ultrashield 10 is ready for use when theprotective pouch 62 is removed from the probe cover 20. Thus, anyadditional packaging to reduce or eliminate water vapor loss or loss ofcouplant is not needed and the probe cover 20 may be packaged in aconventional fashion.

Replenishment

As mentioned previously, it may be appreciated that although the bodycontact layer 34 controls elution of couplant from the couplant layer32, resisting quick emptying, it is possible for the couplant toeventually empty. This typically occurs during lengthy procedures inwhich the probe is heavily used. In such instances, the couplant layer32 may be re-filled with couplant through the body contact layer 34. Forexample, the body contact layer 34 may be placed into couplant to allowthe couplant to absorb through the controlled openings of the layer 34and into the couplant layer 32 for replenishment.

In other embodiments, the couplant layer 32 may be refilled with areplenishment mechanism. FIG. 18 illustrates an example replenishmentmechanism 70 comprising a lumen 72 fluidly connected with a fitting 74,such as a luer connection. In this embodiment, the ultrashield 10 isincorporated into a probe cover 20 and the lumen 72 extends along atleast a portion of the cover 20 to the couplant layer 32 of theultrashield 10. Here, the lumen 72 is formed within a tubing or catheterwhich is affixed to an outside surface the probe cover 20. It may beappreciated that the tubing or catheter having the lumen 72 mayalternatively be integral with the probe cover 20. Or the lumen 72 maybe formed directly into the probe cover 20. In any case, a device 76carrying supplemental couplant, such as a syringe, may be attached tothe fitting 74 for delivery of the supplemental couplant from the device76, through the lumen 72 and to the couplant layer 32, as needed. Thedevice 76 may then be removed when not in use. FIG. 19 illustratesanother embodiment of a replenishment mechanism 70. In this embodiment,the replenishment mechanism 70 comprises lumen 80 that is prefilled withcouplant and is connected with an activation mechanism 82. In thisembodiment, the activation mechanism 82 comprises a capsule or flexiblepouch that is also pre-filled with couplant. Upon activating themechanism 82, such as squeezing the capsule, the couplant moves throughthe lumen 80 to the couplant layer 32. The quantity of deliveredcouplant is controlled by the activation of the mechanism 82. It may beappreciated that alternatively the lumen 80 may not be prefilled,wherein the lumen 80 receives couplant from the prefilled activationmechanism 82. Likewise, the lumen 80 may be prefilled while theactivation mechanism 82 is not prefilled, the activation mechanism 82causing the couplant in the lumen 80 to be delivered to the couplantlayer 32. It may be appreciated that the lumen 80 may be formed within atubing or catheter which is affixed to an outside surface the probecover 20. It may be appreciated that the tubing or catheter having thelumen 80 may alternatively be integral with the probe cover 20. Or thelumen 80 may be formed directly into the probe cover 20.

OTHER EMBODIMENTS

In addition to probes that can be moved across the surface of the body,some probes are designed to be inserted through various openings of thebody (e.g. vagina, rectum, esophagus) so that they can get closer to theorgan being examined (e.g. uterus, prostate gland, stomach). Gettingcloser to the organ can allow for more detailed views. Thus, a varietyof types of ultrasound probes 14 are available with different shapes andsizes. Likewise, ultrasound probes 14 can have different shapesfaceplaces 12, particularly curved faceplates 12. It may be appreciatedthat ultrashields 10 of the present invention may have various shapesand dimensions to accommodate various types of probes 14. FIG. 20Aillustrates an example probe 14 having a curved faceplate 12. FIG. 20Billustrates an embodiment of an ultrashield 10 having a correspondinglycurved shape so as to accommodate the curved faceplate 12. Likewise,FIG. 21A illustrates another example probe 14, this one having a smallercurved faceplate 12. FIG. 21B illustrates an embodiment of anultrashield 10 having a correspondingly curved shape so as toaccommodate the curved faceplate 12. FIG. 22A illustrates an exampleprobe having a round or circular faceplate 12. FIG. 22B illustrates anembodiment of an ultrashield 10 having a correspondingly round orcircular shape so as to accommodate the faceplate 12. FIG. 23Aillustrates an example probe 14 having a square faceplate 12. FIG. 23Billustrates an embodiment of an ultrashield 10 having a correspondinglysquare shape so as to accommodate the square faceplate 12. FIG. 24Aillustrates an example probe 14 having a rectangular faceplate 12disposed along a side of an elongate probe housing 16. FIG. 24Billustrates an embodiment of an ultrashield 10 having a correspondinglyrectangular shape so as to accommodate the rectangular faceplate 12. Itmay be appreciated that the ultrashields 10 may be shaped to accommodateany style of probe 14. In particular, the couplant layer 32 is sized andconfigured to cover the faceplate 12 of the probe 14 with which it is tobe used and the outside edge of the ultrashield 10 may be sized andconfigured to desirably adhere to the probe housing 16. Thus, forexample, the outside edge of the ultrashield 10 may have a circularshape while the couplant layer 32 within the ultrashield 10 may have asquare shape. It may also be appreciated that in some embodiments, theoutside edge of the ultrashield 10 may be trimmed at the time of use todesirably conform and adhere to the probe housing 16.

It may be appreciated that in some embodiments, the body is a human bodyand in other instances the body is the body of an animal or object.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

What is claimed is:
 1. A device comprising: a couplant layer comprisinga couplant material comprising a hydrogel configured to retain water ina colloidal condition and configured to be formed into a self-standingsheet, the couplant layer having a couplant flowable from the couplantmaterial, wherein the couplant comprises the water; and at least oneexternal layer having a plurality of openings and coupled to thecouplant layer, at least one of the at least one external layercomprising an adhesive, wherein the couplant layer and the at least oneexternal layer are flexible and configured to allow ultrasound wavetransmission through a surface while transmitting ultrasound from anultrasound probe, one of the at least one external layer comprising anouter surface body contact layer that is plasma treated or coated with afine film of biocompatible material to reduce friction.
 2. The device ofclaim 1, wherein the couplant layer comprises a rectangular shapeapproximately 2.5 inches long and 0.5 inches wide.
 3. The device ofclaim 1, wherein the outer surface body contact layer curves as toattach to the ultrasound probe.
 4. The device of claim 1, wherein theouter surface body contact layer is configured to control an amount andrate of couplant dispensed.
 5. The device of claim 1, wherein the outersurface body contact layer is configured to be placed into the couplantand configured to allow the couplant to absorb through the plurality ofopenings.
 6. The device of claim 1, wherein the plurality of openingscomprise openings that all have a uniform size.
 7. The device of claim1, wherein each of the openings has a size from 0.2 to 2.0 microns. 8.The device of claim 1, wherein each of the openings has a size from 0.5to 5 microns.
 9. The device of claim 1, wherein each of the openings isa 1 micron opening.
 10. The device of claim 1, wherein each of theopenings is a 2 micron opening.
 11. The device of claim 1, wherein eachof the openings is a 3 micron opening.
 12. The device of claim 1,wherein each of the openings is a 4 micron opening.
 13. The device ofclaim 1, wherein each of the openings is a 10 micron opening.
 14. Thedevice of claim 1, wherein each of the openings has a size from 0 to 10microns.
 15. The device of claim 1, wherein the at least one externallayer comprises a stretchable surface.
 16. A system, comprising: a firstlayer comprising a couplant material comprising a hydrogel configured toretain water in a colloidal condition and configured to be formed into aself-standing sheet, the first layer having a couplant flowable from thecouplant material, wherein the couplant comprises the water; and atleast one second layer having a plurality of openings and coupled to thefirst layer, at least one of the at least one second layer comprising anadhesive, wherein the first layer and the at least one second layer areflexible and configured to allow ultrasound wave transmission through asurface while transmitting ultrasound from an ultrasound probe, one ofthe at least one second layer comprising an outer surface body contactlayer that is plasma treated or coated with a fine film of biocompatiblematerial to reduce friction.
 17. The system of claim 16, furthercomprising a third layer coupled to the first layer that connects withthe ultrasound probe and comprises a flexible film.
 18. The system ofclaim 17, wherein the third layer comprises an adhesive on one side ofthe third layer that adheres to the ultrasound probe.
 19. The system ofclaim 18, further comprising a first packaging layer and a secondpackaging layer held within a packaging pouch that holds the firstlayer, the at least one second layer, and the third layer therein.